java深copy (伪深copy)【原】
Teacher.java
package test.clone; /** * 老师 * 深copy需要实现Cloneable接口 * @author King * */ public class Teacher implements Cloneable { private String name; private int age; public String getName() { return name; } public void setName(String name) { this.name = name; } public int getAge() { return age; } public void setAge(int age) { this.age = age; } @Override public String toString() { return "Teacher [name=" + name + ", age=" + age + "]"; } public Object clone() throws CloneNotSupportedException { return super.clone(); } }
Student.java
package test.clone; /** * 学生 * 浅copy需要实现Cloneable接口 * @author King * */ public class Student implements Cloneable { private String name; private int age; private Teacher teacher; public String getName() { return name; } public void setName(String name) { this.name = name; } public int getAge() { return age; } public void setAge(int age) { this.age = age; } public Teacher getTeacher() { return teacher; } public void setTeacher(Teacher teacher) { this.teacher = teacher; } @Override public String toString() { return "Student [name=" + name + ", age=" + age + ", Teacher=" + teacher + "]"; } //浅copy public Object clone() throws CloneNotSupportedException { return super.clone(); } /** * 浅copy (同clone()方法) * 浅copy只对基本类型和String类型做全新复制, * 属性对象引用是不会全新复制的,最终新copy出来的属性对象引用的还是同一个堆内存区域,比如teacher属性 * @return * @throws CloneNotSupportedException * ...... * @time 2018年1月26日 下午8:07:11 * @author King */ public Object shallowClone() throws CloneNotSupportedException { return super.clone(); } /** * 伪深copy * 这种伪深copy模式,其实还是使用了浅copy技术,只是把属性对象再次赋了新的浅copy. * 当对象比较简单时可以用这种模式,因为它比序列化深copy要来得快,还是定制化copy哪些属性 * @return * @throws CloneNotSupportedException * ...... * @time 2018年1月26日 下午8:09:39 * @author King */ public Object deepClone() throws CloneNotSupportedException { Student stu = (Student) super.clone(); Teacher t2 = (Teacher) teacher.clone(); stu.setTeacher(t2); return stu; } }
FakeDeepCopy.java
伪深copy调用样例
package test.clone; /** * fakeDeepCopy,其实是一种伪深copy,对象对比简单时可以使用这种技术
* * @author King * */ public class FakeDeepCopy { public static void main(String[] args) { Teacher techarAAA = new Teacher(); techarAAA.setName("Teacher AAA"); techarAAA.setAge(30); Student studentAAA = new Student(); studentAAA.setName(new String("Student AAA")); studentAAA.setAge(15); studentAAA.setTeacher(techarAAA); System.out.println("学生复制前studentAAA:" + studentAAA); try { Student studentCopy = (Student) studentAAA.clone(); Teacher teacherCopy = studentCopy.getTeacher(); studentCopy.setName(new String("Student BBB")); studentCopy.setAge(20); teacherCopy.setName("Teacher BBB"); teacherCopy.setAge(45); studentCopy.setTeacher(teacherCopy); System.out.println("学生复制后studentAAA:" + studentAAA); System.out.println("学生复制后studentCopy:" + studentCopy); } catch (CloneNotSupportedException e) { e.printStackTrace(); } } }
以上深copy主要通过各层浅copy实现.
真正完整深copy可通过序列化的方式.
感觉空虚寂寞,只是因为你无所关注,无处付出。